Field of the Invention
Printing on a continuous web in an offset web press is normally performed by use of a thin, flexible plate whose printing surface has been subjected to ink and to water. The plate roll is manufactured with a slot that extends across its entire length to receive a lockup mechanism for holding the flexible plate tightly against the outer surface of the plate roll. In the usual situation, the plate has inwardly turned tabs or flanges on each end thereof, the flange on one end engaging directly the edge formed by the slot and the flange on the other end being engaged by the lockup mechanism to pull the plate tight. In other instances, provision may be made for the lockup mechanism to engage both ends of the plate to hold it in position.
In manufacturing plate rolls and plate lockups, it is desired to keep the width of the slot gap as narrow as possible to reduce vibration or bouncing resulting from impact of the edges of the slotted area with the cooperating adjoining blanket roll. However, when narrow gaps are used, it has heretofore been necessary to remove the plate roll bearer rings to change lockup parts. Removal of lockup parts without partial disassembly of the plate roll support system has been confined to rolls having comparatively wide gaps.